Balanced valve element and pressure regulating valve

ABSTRACT

The present invention relates to a balancing valve spool and a pressure regulating valve comprising the balancing valve spool. The balancing valve spool comprises a valve rod; a piston sleeve fixed on the valve rod; and a fixing piece sleeved between the valve rod and the piston sleeve and arranged along a direction in parallel with an axis of the valve rod. In one embodiment of the present invention, by connecting the fixing piece onto an actuator of the valve and arranging the fixing piece between the valve rod and the piston sleeve along the direction of the axis of the valve rod, an effect of guiding the valve rod is achieved and a sealing effect of isolating inlet pressure and outlet pressure is simultaneously achieved. Compared with the related arts, this design has the advantage of simple structure.

FIELD OF THE INVENTION

The present invention belongs to the field of fluid control, specifically relates to a balancing valve spool and further relates to a pressure regulating valve comprising the balancing valve spool.

BACKGROUND OF THE INVENTION

In the design of a pressure regulator, since inlet pressure acts on a valve seat to produce an additional force which directly influences the performance of a pressure regulator product, a structure of a balancing valve spool is usually designed.

FIG. 1 shows a designing method of a balancing valve spool at present. In this designing method, one end of an n-shaped diaphragm is fixedly connected with a valve rod and the other end of the n-shaped diaphragm is fixedly connected with a valve body or a connecting piece (for connecting the valve body with an actuator), wherein the end, which is connected with the valve rod, of the n-shaped diaphragm needs to be fixed on the valve rod by using a fixing piece. From FIG. 1, it can be seen that this balancing valve spool has the disadvantages of complex structure, the greater number of parts and relatively higher cost.

FIG. 2 is another designing method of a balancing valve spool at present. This designing method adopts a valve rod mobile piston structure, wherein an O-ring 20 is arranged on a piston sleeve to achieve a sealing effect of isolating inlet pressure and outlet pressure. However, this kinds of structure is not beneficial to guide (since the O-ring has elasticity, the valve rod will shake); and in addition, the smoothness of a cylindrical surface, in contact with the O-ring, of the piston sleeve is difficult to guarantee, a guide sleeve 30 needs to be additionally arranged for the purpose of guide, an additional space needs to be added in a longitudinal space of the valve in order to install the guide sleeve and thereby the structure of the valve is more complex.

SUMMARY OF THE INVENTION

In order to solve the problem that the structure of the existing balancing valve spool is complex, the present invention provides a balancing valve spool and a pressure regulating valve comprising the balancing valve spool.

In one aspect, the embodiment of the present invention discloses a balancing valve spool, comprising:

-   -   a valve rod;     -   a piston sleeve fixed on the valve rod; and     -   a fixing piece sleeved between the valve rod and the piston         sleeve and arranged along a direction in parallel with an axis         of the valve rod.

The above-mentioned piston sleeve comprises a sleeve body and a bottom portion, the bottom portion of the piston sleeve is fixed on the valve rod and a first gap is configured between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod.

A first sealing part is arranged between the above-mentioned fixing piece and the sleeve body of the piston sleeve.

In another aspect, the embodiment of the present invention discloses a pressure regulating valve, comprising:

-   -   a valve body provided with a valve chamber;     -   an actuator fixedly connected with the valve body; and     -   the above-mentioned balancing valve spool.     -   The above-mentioned fixing piece is fixedly connected onto the         actuator.     -   The above-mentioned actuator comprises:     -   a pressure regulating device;     -   a diaphragm cap assembly comprising a first diaphragm cap and a         second diaphragm cap, the first diaphragm cap being connected         with the pressure regulating device, the second diaphragm cap         being connected with the valve body, and the first diaphragm cap         and the second diaphragm cap being matched with each other to         form a hollow internal portion; and     -   a diaphragm assembly comprising a diaphragm, the diaphragm being         located between the first diaphragm cap and the second diaphragm         cap.

The above-mentioned fixing piece is fixed on the second diaphragm cap; or the fixing piece and the second diaphragm cap are integrally molded.

The above-mentioned pressure regulating valve further comprises guide sleeves which are fixed on the second diaphragm cap and the guide sleeves are rings which surround a cross section of the valve rod.

Alternatively, the above-mentioned pressure regulating valve further comprises guide sleeves which are located on an outer circumference of the valve rod.

The number of the above-mentioned guide sleeves is at least two.

The bottom portion of the above-mentioned piston sleeve comprises an extending portion which extends outwards along an axis direction of the valve rod and the extending portion is closely fixed onto the valve rod.

The above-mentioned valve rod and the piston sleeve are integrally molded.

A second sealing part is arranged at a connection between the above-mentioned valve rod and the bottom portion of the piston sleeve.

In one embodiment of the present invention, by connecting the fixing piece onto the actuator of the valve and arranging the fixing piece between the valve rod and the piston sleeve along the axis direction of the valve rod, an effect of guiding the valve rod is achieved and a sealing effect of isolating inlet pressure and outlet pressure is simultaneously achieved. Compared with the related arts, this design has the advantage of simple structure.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural schematic diagram of a balancing valve spool of a first one of related arts;

FIG. 2 is a structural schematic diagram of a balancing valve spool of a second one of related arts;

FIG. 3 is a structural schematic diagram of a balancing valve spool provided by a first one of embodiments of the present invention;

FIG. 4 is a structural schematic diagram of a pressure regulating valve provided by a first one of embodiments of the present invention;

FIG. 5 is a structural schematic diagram of a balancing valve spool provided by a second one of embodiments of the present invention;

FIG. 6 is a structural schematic diagram of a balancing valve spool provided by a third one of embodiments of the present invention.

DESCRIPTION OF NUMERAL REFERENCES

11-valve rod, 111-first end, 112-second end, 12-piston sleeve, 121-sleeve body, 122-bottom portion, 123-extending portion, 13-valve seat, 14-fixing piece, A-first gap, B-second gap, C-third gap, D-fourth gap, 15-first sealing part, 16-second sealing part, 17-guide sleeve, 2-valve body, 21-inlet, 22-outlet, 23-valve chamber, 231-first area, 232-second area, 233-valve port, 311-first diaphragm cap, 312-second diaphragm cap, 321-diaphragm, 322-first diaphragm plate, 323-second diaphragm plate, 331-spring, 332-regulating rod, 3321-third end, 3322-fourth end, 4-third sealing part.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solution of the present invention will be further described below in combination with the drawings and the embodiments.

A balancing valve spool disclosed by this embodiment is located in a pressure regulating valve. As shown in FIG. 4, the pressure regulating valve comprises a valve body, the balancing valve spool and an actuator. The valve body 2 comprises an inlet 21, an outlet 22 and a valve chamber 23. The actuator is fixedly connected with the valve body. Inlet pressure of the pressure regulating valve provided by the present disclosure can be gas pressure and can also be liquid pressure. Correspondingly, outlet pressure can be gas pressure and can also be liquid pressure.

As shown in FIG. 3 and FIG. 4, the balancing valve spool comprises a valve rod 11, a piston sleeve 12, a valve seat 13 and a fixing piece 14. The valve rod 11 comprises a first end 111 and a second end 112, wherein the first end 111 of the valve rod is placed in the actuator of the valve and the second end 112 of the valve rod is fixed in the valve seat 13. The valve seat 13 is movably arranged in the valve chamber 23. The piston sleeve 12 comprises a sleeve body 121 and a bottom portion 122, wherein the bottom portion 122 of the piston sleeve is fixed on the valve rod 11 and a first gap A is configured between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod. The fixing piece 14 is fixed on the actuator of the valve and the fixing piece 14 is arranged between the valve rod 11 and the piston sleeve 12 along an axis direction of the valve rod. The valve rod 11, the piston sleeve 12 and the valve seat 13 can move along the axis direction of the valve rod.

The fixing piece 14 herein has an effect of guiding the valve rod 11 and simultaneously has a sealing effect of isolating inlet pressure and outlet pressure. In order to guarantee the sealing effect, a first sealing part 15 can be arranged between the fixing piece 14 and the sleeve body 121 of the piston sleeve 12. The first sealing part 15 can be an O-ring and can also be sealing packing, etc. It needs to be stated that the seal described here is a dynamic seal as the fixing piece 14 and the piston sleeve 12 move relatively. The purpose of isolating the inlet pressure and the outlet pressure is to enable the pressure regulating valve to maintain stable outlet pressure. However, the inlet pressure is certainly higher than the outlet pressure. If the inlet pressure and the outlet pressure are not isolated, the outlet pressure will always rise.

In order to guarantee the valve rod 11, the piston sleeve 12 and the valve seat 13 to move along the axis direction of the valve rod, as shown in FIG. 3, in this embodiment, a second gap B is configured between the fixing piece 14 and the bottom portion 122 of the piston sleeve, a third gap C is configured between the actuator of the pressure regulating valve and the piston sleeve and a fourth gap D is configured between the valve body and the piston sleeve.

The valve chamber 23 comprises a first area 231 communicated with the inlet 21, a second area 232 communicated with the outlet 22, and a valve port 233 communicated with the first area 231 and the second area 232. When the valve rod 11 moves, the valve seat 13 moves between the valve port 233 and the second area 232.

The actuator comprises a diaphragm cap assembly, a diaphragm assembly and a pressure regulating device, wherein the diaphragm cap assembly comprises a first diaphragm cap 311 and a second diaphragm cap 312, the first diaphragm cap 311 is connected with the pressure regulating device, the second diaphragm cap 312 is connected with the valve body 2, and the first diaphragm cap 311 and the second diaphragm cap 312 are matched with each other to form a hollow internal portion. The diaphragm assembly comprises a diaphragm 321, a first diaphragm plate 322 and a second diaphragm plate 323, the diaphragm 321 is pressed between the first diaphragm plate 322 and the second diaphragm plate 323, the diaphragm 321 is located between the first diaphragm cap 311 and the second diaphragm cap 312, the first diaphragm plate 322 is located within a cavity formed by the diaphragm 321 and the first diaphragm cap 311, and the second diaphragm plate 323 is located within a cavity formed by the diaphragm 321 and the second diaphragm cap 312. The pressure regulating device comprises a spring 331 and a regulating rod 332, the spring 331 is located inside of the first diaphragm cap 311, the regulating rod 332 comprises a third end 3321 and a fourth end 3322, the third end 3321 of the regulating rod penetrates through the first diaphragm cap 311 and is in contact with the spring 331, the fourth end 3322 of the regulating rod is suspended and the regulating rod is fixed on the first diaphragm cap 311.

The first diaphragm plate 322 further has effects of supporting the spring 331 and transferring spring force. The second diaphragm plate 323 further has an effect of isolating the outlet pressure and the exterior.

Specifically, the first end 111 of the valve rod penetrates through the diaphragm 321 and is fixed on the first diaphragm plate 322. The fixing piece 14 is fixed on the second diaphragm cap 312. The fixing piece 14 can be integrally molded with the second diaphragm cap 312 and can also be fixed on the second diaphragm cap 312 as an independent part. As shown in FIG. 4, the fixing piece 14 is integrally molded with the second diaphragm cap 312. It is to be noted that the fixing piece 14 is not limited to be fixed on the second diaphragm cap 312 and can be fixed with the actuator or the valve body as long as the essence of the present invention is satisfied.

In order to enable the valve rod to move along a straight line to achieve a guide effect, the pressure regulating valve in this embodiment further comprises guide sleeves 17, the guide sleeves 17 are fixed on the second diaphragm cap 312, the guide sleeves 17 are rings which surround a cross section of the valve rod, and the number of the guide rings as shown in FIG. 3 is two. Of course, the number of the guide rings can also be one or more; if a guide surface in contact with the valve rod 11 is smooth enough, there may be no guide ring. FIG. 6 shows a balancing valve spool without a guide sleeve. The guide sleeves 17 can be made of brass, PTFE, etc. The guide sleeves 17 have an effect of guiding the valve rod 11 and also have an effect of reducing friction.

Alternatively, the guide sleeves 17 can also be located on an outer circumference of the valve rod 11 (instead of the second diaphragm cap of the actuator) and are approximately located on the outer circumference of a middle position of the valve rod, which refers to a position between the first end 111 of the valve rod and the piston sleeve 12.

During manufacturing, the valve rod 11 and the piston sleeve 12 can be two independent parts and can also be integrally molded. In case of two independent parts, in order to isolate the inlet pressure and the outlet pressure, a second sealing part 16 is arranged at a connection between the valve rod 11 and the bottom portion 122 of the piston sleeve to achieve a sealing effect. The second sealing part 16 can be an O-ring and can also be sealing packing, etc. It is to be noted that the seal described here is a static seal as the fixing piece 14 and the piston sleeve 12 are relatively static. The purpose of isolating the inlet pressure and the outlet pressure is to enable the pressure regulating valve to maintain stable outlet pressure. However, the inlet pressure is certainly higher than the outlet pressure. If the inlet pressure and the outlet pressure are not isolated, the outlet pressure will always rise.

It is to be noted that the main effect of the piston sleeve is to bear an upward balancing force to balance downward pressure produced by the gas inlet pressure (or liquid inlet pressure) to the valve seat. Therefore, other piston sleeve structures can be used as long as the essence of the present invention is satisfied, and the piston sleeve structures are not limited to that as shown in FIG. 3 and FIG. 4. For example, in order to facilitate manufacturing in the process, the bottom portion 122 of the piston sleeve can also comprise an extending portion 123 which extends outwards along the axis direction of the valve rod and the extending portion 123 is closely fixed on the valve rod 11, as shown in FIG. 5 and FIG. 6.

The second diaphragm cap 312 of the actuator and the valve body 2 are fixedly connected through screws as shown in FIG. 4, and other fixed connecting manners can also be adopted. If a contact part between the second diaphragm cap 312 and the valve body 2 is not well sealed, a third sealing part 4 can be arranged at the contact position to isolate medium in the valve body and the external environment, so as to achieve a sealing effect. The third sealing part can be an O-ring and can also be sealing packing, etc.

By adopting the design in the above-mentioned embodiment, the structure of the existing pressure regulating valve (mainly the balancing valve spool) is simplified, the number of parts is reduced, the cost is reduced and the additional space does not need to be added in the longitudinal direction for the guide sleeves of the valve rod.

As shown in FIG. 4, the working principle of the above-mentioned pressure regulating valve is that gas or liquid enters the valve along the first area from the inlet, inlet pressure acts on the valve seat to produce downward pressure, and the effect of the balancing valve spool is to produce an upward force to balance the downward pressure, wherein the bottom portion of the piston sleeve has an effect of bearing the upward pressure. A user can set the needed outlet pressure by regulating the spring force through the regulating rod as desired. Under the effect of the spring force, the valve rod will be enabled to move up and down and the valve seat moves up and down between the second area and the valve port. When the valve seat moves to the bottommost end, the opening of the valve port is the maximum and the outlet pressure of the second area becomes smaller; and when the valve seat moves up, the opening of the valve port becomes smaller, and the outlet pressure of the second area becomes larger; the valve rod does not stop moving until the outlet pressure reaches a needed value, and finally the pressure regulating valve is in a balanced state.

At the beginning of the design of the balancing valve spool product, the force produced by the inlet pressure to the valve seat can be changed by changing the contact area of the bottom portion of the piston sleeve with the gas inlet pressure (or liquid inlet pressure) according to the actual needs, so as to satisfy the actual needs. At the beginning of the design of the pressure regulating valve product, the most suitable diaphragm size can be found by adjusting the size of the diaphragm to output the needed outlet pressure according to the actual needs.

It is to be noted that the term “comprise”, “comprising” or any other variants in this disclosure intends to cover nonexclusive inclusion, so as to enable a process, method, object or equipment comprising a series of elements to not only comprise such elements, but also further comprise other elements which are not clearly listed, or further comprise intrinsic elements of such process, method, object or equipment. Under the situation of no more limitations, an element defined by a statement “comprising one . . . ” does not exclude the situation that other same elements also exist in the process, method, object or equipment comprising such elements.

Although terms “first”, “second”, “third” and the like are used to describe various components, parts or portions, such components, parts or portions shall not be limited by such terms; and such terms can only be used for distinguishing a component, part or portion. When terms such as “first” and “second” and other numerical terms are used herein, it does not include sequence or order, unless otherwise clearly stated in the context. Therefore, under the situation of not departing from the illustration of the exemplary embodiments, the first component, part or portion below can be interpreted as a term “first element, part or portion”.

The embodiments described above are just preferred embodiments of the present invention and are not used for limiting the protection range of the present invention. Any modification, equivalent replacement, improvement and the like made within the spirit and the principle of the present invention shall be included in the protection range of the present invention. 

1. A balancing valve spool, characterized in that the balancing valve spool comprises: a valve rod; a piston sleeve fixed on the valve rod; and a fixing piece sleeved between the valve rod and the piston sleeve and arranged along a direction in parallel with an axis of the valve rod.
 2. The balancing valve spool according to claim 1, characterized in that the piston sleeve comprises a sleeve body and a bottom portion, the bottom portion of the piston sleeve is fixed on the valve rod and a first gap is configured between an inner wall of the sleeve body of the piston sleeve and an outer wall of the valve rod.
 3. The balancing valve spool according to claim 2, characterized in that a first sealing part is arranged between the fixing piece and the sleeve body of the piston sleeve.
 4. A pressure regulating valve, characterized in that the pressure regulating valve comprises: a valve body provided with a valve chamber; an actuator fixedly connected with the valve body; and a balancing valve spool according to any one of claims 1-3.
 5. The pressure regulating valve according to claim 4, characterized in that the fixing piece is fixedly connected onto the actuator.
 6. The pressure regulating valve according to claim 4, characterized in that the actuator comprises: a pressure regulating device; a diaphragm cap assembly comprising a first diaphragm cap and a second diaphragm cap, the first diaphragm cap being connected with the pressure regulating device, the second diaphragm cap being connected with the valve body, and the first diaphragm cap and the second diaphragm cap being matched with each other to form a hollow internal portion; and a diaphragm assembly comprising a diaphragm, the diaphragm being located between the first diaphragm cap and the second diaphragm cap.
 7. The pressure regulating valve according to claim 6, characterized in that the fixing piece is fixed on the second diaphragm cap; or the fixing piece and the second diaphragm cap are integrally molded.
 8. The pressure regulating valve according to claim 6, characterized in that the pressure regulating valve further comprises guide sleeves which are fixed on the second diaphragm cap and the guide sleeves are rings which surround a cross section of the valve rod.
 9. The pressure regulating valve according to claim 4, characterized in that the pressure regulating valve further comprises guide sleeves which are located on an outer circumference of the valve rod.
 10. The pressure regulating valve according to claim 8 or 9, characterized in that the number of the guide sleeves is at least two.
 11. The pressure regulating valve according to claim 4, characterized in that the bottom portion of the piston sleeve comprises an extending portion which extends outwards along an axis direction of the valve rod and the extending portion is closely fixed onto the valve rod.
 12. The pressure regulating valve according to any one of claims 4-9 and 11, characterized in that the valve rod and the piston sleeve are integrally molded.
 13. The pressure regulating valve according to any one of claims 4-9 and 11, characterized in that a second sealing part is arranged at a connection between the valve rod and the bottom portion of the piston sleeve. 